Rotating Annulus Sealing for Gas Turbine Engine Inter-stage Leakage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing inter-stage seals in gas turbine engines require additional structural support and secondary airflow systems to prevent gas leakage, which increases complexity, weight, and reduces engine performance.
Innovation Solution
A rotating annulus is mounted directly to the rotor disc to define part of the gas flow path boundary, eliminating the need for a static guide vane and reducing the load on stationary components, and providing improved sealing through interlocking profiles and a sealing feature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a static inter-stage seal structure coupled to a stationary guide vane is used, then sealing is provided, but the guide vane is subjected to additional load requiring stronger materials or structural support, increasing weight and complexity
Solution Approach 1:
The patent applies the dynamics principle by replacing the static inter-stage seal structure with a rotating annulus that moves with the rotor discs. This dynamic configuration eliminates the need for additional structural support on stationary guide vanes, as the sealing function is transferred to the rotating component that naturally follows the rotor motion, thereby reducing weight and complexity while maintaining sealing reliability
2Reliability
If additional sealing is provided at the rotor blade and guide vane interface, then gas leakage is reduced, but secondary airflow systems are required which consume energy and reduce overall engine performance
Solution Approach 1:
The patent extracts the sealing function from the stationary guide vane and rotor blade interfaces and relocates it to the rotating annulus. This extraction eliminates the need for secondary airflow systems that would otherwise be required to seal the gaps at the rotor blade-guide vane interface, thereby reducing energy consumption and improving overall engine performance while maintaining effective sealing
3Device complexity
If a rotating annulus is mounted directly to the rotor disc, then sealing is improved and complexity is reduced, but the mounting structure must accommodate precise rotational alignment
Solution Approach 1:
The patent merges the sealing function with the rotor disc assembly by mounting the rotating annulus directly to the rotor disc. This integration combines multiple functions (rotor support, sealing, and alignment reference) into a unified structure, eliminating the need for separate sealing components and reducing overall complexity while achieving precise rotational alignment through the integrated design
Data Source
AI summary
A turbomachine for a gas turbine engine, comprising: a rotor disc arranged to rotate about a fixed central axis. A plurality of rotor blades connected to the rotor disc, wherein the rotor blades extend within a gas flow path. A rotating annulus is arranged to rotate in a fixed rotational alignment relative to the rotor disc. An outer surface of the rotating annulus is arranged to define part of the boundary of the gas flow path. A gas turbine engine for an aircraft and a method of defining the boundary of a gas flow path within a turbomachine is also disclosed.